�мҺӻ��������ǽ���������ڵ���Ҫ���壬��������ҪΪ�д�������ĸ���������ҡ��ʯ LA- - ICP- - MS U- -Pb ���ѧ�о��������мҺӻ������γ��� 149 ± 2 Ma������٪�������мҺӻ����� SiO 2 �ĺ���Ϊ 64. 58% ��72. 05%����Խϸ�; A/CNK ֵΪ 0. 98 �� 1. 22��΢��Ԫ��������ʾ���мҺӻ����Ҹ�����������ʯԪ�� (LILE) ��b��Ba��K��ǿ�ҿ���߳�ǿԪ�� (HFSE) Nb��Ta��Ti��P; ϡ��Ԫ��������ʾ��ϡ��ǿ�Ҹ�������ϡ�����ȿ�����΢�����쳣����ʯ�� Nb/La �� Nd/Th ��ֵ��ʾ��Դ�����ҵ���������b/Sr ��ֵ��ʾ�����в����Դ���ʻ��롣���������ʷ�����Ϊ��٪�޼Ϳ�ʼ��̫ƽ������ŷ�Ǵ�½�ĸ����������ģ�Դ�ҽ����֣����µؿ����ʲ��������γ��мҺӻ����ҡ�

Luanjiahe granite is the important rocks in Jiaodong goldfields region�� composed mainly of medium- coarse grained biotite monzonitic granites�� LA - -ICP - -MS zircon U - -Pb dating shows that the Luanjiahe granite formed in the Late Jurassic (aged in 149 ±2 Ma)�� The SiO 2 content of Luanjiahe granite is higher as 64. 58% to 72. 05%��while A/CNK is 0. 98 to 1. 22�� The granite is enriched in large ion lithophile elements (LILE) ��b�� Ba��K�� and strongly depleted in HFSE (Nb��Ta��Ti and P)�� The ��EE patterns demonstrate strong enrichment in L��EE and depletion in H��EE��and sightly positive anomaly in Eu�� The ratio of the Nb/La and Nd/Th shows char- acteristics of the crust granites�� The ratio of ��b/Sr shows possible mixture of part of the mantle source materials�� Combined with the regional geological analysis��it is suggested that the subduction of the Pacific plate to Eurasian Land triggered massive mantle- derived magma under- plating since Jurassic��led to a partial melting of crust material and the Luanjiahe granite��